An Off-Line DPPH-GC-MS Coupling Countercurrent Chromatography Method for Screening, Identification, and Separation of Antioxidant Compounds in Essential Oil.

Guang-Lei Zuo,Xiang Wang,Sheng-Qiang Tong,Chao-Yue Wang,Soon Sung Lim,Hyun Yong Kim

doi:10.3390/antiox9080702

Abstract

Essential oils are an important source of natural antioxidants and multiple methods have been established for evaluation of their overall antioxidant activity, however, the antioxidant activities of their compounds are less investigated. In the present study, the hyphenation of 2,2′-diphenyl-1-picrylhydrazyl (DPPH)-gas chromatography (GC)-mass spectrometry (MS) offline and high-speed countercurrent chromatography (HSCCC) is established for efficient screening, identification, and isolation of antioxidants from essential oils and applied to the essential oil of Curcuma wenyujin Y.H. Chen et C. Ling. Five compounds are preliminarily screened as antioxidants using DPPH-GC according to the reduction of GC peak areas of each compound after reaction with DPPH and then identified as eucalyptol (7.66%), camphor (2.34%), δ-elemene (1.15%), β-elemene (7.10%), and curzerene (15.77%) using GC-MS. Moreover, these five compounds are isolated by HSCCC using two solvent systems, n-hexane-acetonitrile-ethanol (5:3:2, v/v) and n-hexane-acetonitrile-acetone (4:3:1, v/v), and subjected to DPPH scavenging assay. Camphor, δ-elemene, and β-elemene show weak DPPH scavenging activity, while curzerene and eucalyptol show moderate DPPH scavenging activity. Notably, a significant synergistic effect on DPPH scavenging is found between curzerene and eucalyptol. The result demonstrated that off-line DPPH-GC-MS coupling CCC is an efficient method for screening, identification, and separation of antioxidant compounds in essential oil

Highlights

Essential oils are fluid mixtures obtained from fragrant plants, which have been used in cosmetic fragrances, food flavors, and traditional medicines for several centuries [1]
The result demonstrated that off-line DPPH-gas chromatography (GC)-mass spectrometry (MS) coupling countercurrent chromatography (CCC) is an efficient method for screening, identification, and separation of antioxidant compounds in essential oil Keywords: antioxidant; DPPH-GC offline; high-speed countercurrent chromatography (HSCCC); essential oil; curcuma
A rapid and simple strategy for screening, identification, and separation of radical scavengers by off-line DPPH-GC-MS coupling HSCCC method was developed, and it was successfully applied for the investigation of potential antioxidants in C. wenyujin Y.H

Summary

Introduction

Essential oils are fluid mixtures obtained from fragrant plants, which have been used in cosmetic fragrances, food flavors, and traditional medicines for several centuries [1]. Multiple beneficial effects of essential oil, such as antioxidation [2], anti-inflammation [3], antibacterial [4], and anticancer activities [5], have been investigated and applied for prevention and treatment of diseases. Antioxidants 2020, 9, 702 considering that essential oils are relatively safe and widely accepted by consumers [8], the study of essential oil antioxidants is still highly encouraged. The evaluation of the antioxidant activity of essential oils (a mixture of compounds) can be carried out using several methods [10,11,12,13,14,15]. Due to the lack of efficient methods for screening and separation of the potential antioxidant compounds, particular minor antioxidants, from essential oils, the antioxidant activity of the individual compounds from essential oils are usually less studied

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